After filing for bankruptcy protection and going back and forth with Frontier Airlines — again — over a potential acquisition, Spirit Airlines has a new plan.

Spirit Airlines again rejected Frontier Airlines’s latest takeover bid, opting to instead focus on its restructuring process to bolster financial stability.  Spirit, an ultra-low-cost airline,

A merger of America's two largest budget airlines appears increasingly unlikely. Spirit Airlines on Thursday rejected Frontier Airlines' latest proposal for a merger, which would have helped bring the Florida-based carrier out of bankruptcy to join forces with its top competitor.